Why strength training advice for women is mostly wrong

For decades, women have been told they need special workout rules. Don’t lift too heavy. Train around your hormones. Change your workouts throughout the month.

The advice seemed logical. Men have substantially higher testosterone levels, a hormone that plays a major role in muscle growth. “Testosterone increases muscle mass in boys, and so you get an adult 20-year-old man and an adult 20-year-old woman, and there’s going to be differences in baseline muscle size and strength,” says Lauren Colenso-Semple, a researcher and science communicator specializing in female physiology and exercise.

But a growing body of research suggests those differences may matter less than many people assume once training begins. A 2025 meta-analysis published in PeerJ found that women have a similar capacity for muscle growth, known as hypertrophy, as men. While men typically start with more muscle mass, women make comparable relative gains in muscle mass through resistance training.

Once people start exercising, the sex differences disappear quite quickly: “When you think about lifting weights and the magnitude of muscle size and strength that you can gain in response to training, the trajectory is very, very similar in men and women,” says Colenso-Semple.

Although hormones can influence how exercise feels from day to day, there is little evidence that most women need entirely different training programs to build muscle, strength, or fitness. That matters because resistance training remains one of the most powerful tools for improving cardiovascular health, preserving bone density, and supporting healthy aging. But only 27 percent of adult women in the U.S. met the federal guidelines for muscle-strengthening activities in 2020.

Here’s what you need to know about how women should be training.

Why hormones have become central to the conversation

The idea that women should train differently from men didn’t appear out of thin air. Most exercise science research—specifically on resistance training—centered men as study participants, leaving many women wondering whether their own physiology had been adequately considered.

“We have a menstrual cycle. We have highs and lows of estrogen and progesterone, much more drastic than men have changes in their testosterone levels,” says Heather Milton, an exercise physiologist and certified strength and conditioning specialist who teaches a program on perimenopause and menopause for NYU Langone Health.

(Females bodies are uniquely flexible—here’s why that makes them strong.)

Energy levels, sleep quality, recovery, and mood can all shift throughout the menstrual cycle, making it easy to see why many women feel that their workouts shouldn’t feel the same every day of the month.

One of the clearest findings so far relates to perceived exertion—how difficult exercise feels. “If I’m to do the same workout now that I do in my late luteal phase, I might think that it was a really intense workout, but currently if I did it today, I might feel like it was a breeze,” says Milton. “It doesn’t necessarily mean that we have to completely change everything we’re doing phase to phase in our menstrual cycle, but being aware of that is very helpful.”

But understanding why a workout feels harder isn’t the same thing as having evidence that a training program should change.

What social media gets wrong

In recent years, social media influencers, coaches, and wellness companies have increasingly promoted the idea that women should tailor their workouts to the different phases of their menstrual cycle. These cycle-syncing programs may encourage women to lift heavy during one phase, for example, and swap strength training for yoga, walking, or recovery-focused workouts during another.

Researchers, however, haven’t identified an evidence-based protocol for making those kinds of adjustments. “It’s more for us to understand as women, why did that workout feel like it sucked?” says Milton.

(Here’s what lifting weights does to your body—and your mind.)

But feeling worse during a workout doesn’t necessarily mean the workout is less effective. Women can still build muscle, lose fat, improve cardiovascular fitness, and even perform just as powerfully throughout every phase of the menstrual cycle. In some cases, rigid cycle-syncing programs may even work against long-term progress.

Frequent reductions in training volume or intensity can make it harder to stay consistent with strength training or to accumulate enough work to drive meaningful adaptations. “What we want if we want to optimize our ability to adapt to exercise is consistency,” says Colenso-Semple.

Many strict cycle-syncing recommendations also oversimplify the menstrual cycle. Only 13 percent of women have a 28-day cycle (which many programs are based on), and symptoms can vary dramatically from person to person and month to month.

Colenso-Semple argues that bad actors in the wellness space have capitalized on the historical underrepresentation of women in exercise science. “They profit on selling ineffective solutions to women because when you employ one strategy that doesn’t work, guess what? They’re right there waiting to sell you the next one,” she says. “They don’t want you to adopt the habits that actually work because they can’t monetize that.”  

What differences actually have evidence behind them?

While many popular claims about sex-specific training haven’t held up, researchers have identified a handful of physiological differences that may be relevant. A 2020 meta-analysis in the Journal of Strength and Conditioning Research and a 2023 review in the same journal found that women and men both responded similarly to resistance training in terms of muscle growth and lower-body strength. Even untrained women had a higher capacity to increase upper-body strength than men.

That doesn’t mean researchers haven’t identified any sex-specific considerations. One area of growing interest is how hormonal fluctuations throughout the menstrual cycle may influence recovery and injury risk. Milton says that some research suggests an increased risk of ACL tears during the luteal phase.

More research is needed to pinpoint why this increased injury risk may occur, but Milton says that during the luteal phase, progesterone rises, which increases cortisol response and inflammation. “I don’t want that to be a red flag and worry people—our cortisol levels ebb and flow, which is totally fine—but it can also mean that we may need a little bit more recovery time,” she says.

(Why women may get more from exercise than men.)

Still, she cautions that the evidence remains preliminary and is more relevant to athletes participating in high-intensity sports than the average gym-goer. But “having something that is actually evidence-based that can allow you to have a reason to take a rest day or a lower-intensity day, I think, is very valuable,” says Milton.

Women also appear to be more fatigue-resistant than men during certain types of exercise. Studies suggest that women often perform more repetitions at a given percentage of their one-repetition maximum (1RM) than men do. In practice, that may mean a woman can complete more repetitions at 80 percent of her 1RM than a male training partner, even if both are following the same program.

This may help explain why some women find percentage-based strength programs less accurate than expected, or why they need slightly higher repetition ranges to reach failure.

The science is still evolving

After years of debate, the biggest takeaway may be surprisingly simple. The fundamentals that drive fitness adaptations—progressive overload, adequate recovery, consistency, and proper nutrition—work similarly across sexes.

“It's not a male versus female,” says Milton. “It should be tailoring their workouts depending on their medical history, their fitness, and their goals—not just what the media is telling you you should be doing.”

However, Milton cautions that researchers still lack sufficient high-quality data to draw firm conclusions about how hormonal fluctuations influence training outcomes. She says that the next generation of research is moving beyond the question of whether women can train like men and instead asking whether exercise programs tailored to female physiology could produce even better results.

Until researchers have that answer, the evidence suggests that most women can focus less on optimizing around their hormones and more on the fundamentals of getting stronger.